Behavioral impairment associated with small doses of carbon monoxide.

18 young men were subjected to tone-length discrimination tests while in a room where CO was or was not present. No COHb measurements were made. 90-min exposure to 50 ppM CO significantly reduced percent correct answers; less time was required for higher CO concentrations (up to 250 ppM). There was no effect of temperature or humidity. Rats were also exposed to CO and studied with operant behavior schedules of reinforcement. 11-min exposure to 100 ppM CO impaired their ability to judge time. That behavioral psychology provides sensitive methods of assessment of health effects of pollution is suggested.